Angela Bennett (Sandra Bullock) is a systems analyst from Venice, California who telecommutes to Cathedral Software in San Francisco. Her interpersonal relationships are almost completely online and on the phone, with the exception of forgettable interactions with her neighbors and visits to her mother (Diane Baker), who is institutionalized with Alzheimer's disease and often forgets who Bennett is. Bennett's co-worker Dale sends her a floppy disk with a backdoor labeled "π" that permits access to a commonly used computer security system called "Gatekeeper" and sold by Gregg Microsystems. Dale and Bennett agree to meet, but Dale's private plane's navigation system malfunctions and sends the plane into a tower, killing him.

Bennett travels to Cozumel, Mexico on vacation, where she meets Jack Devlin (Jeremy Northam). After seducing Bennett, Devlin pays a mugger to steal her purse as they walk along the beach. He chases the mugger into the foliage and roots through the purse to find the disk before shooting him. He takes Bennett out on his speedboat to kill her as well, but she finds his gun and confronts him. While fleeing with the disk and Devlin's wallet, Bennett's dinghy collides with rocks, destroying the disk and hospitalizing her. She is unconscious for three days.

When Bennett wakes up, she finds that all records of her life have been deleted: She was checked out of her hotel room, her car is no longer at the LAX parking lot, and her credit cards are invalid. Bennett's home is empty and listed for sale. Moreover, because none of the neighbors remember her, they cannot confirm her identity. Bennett's Social Security number is now assigned to a "Ruth Marx," for whom Devlin has entered arrest record by hacking police records. When Bennett calls her desk at Cathedral, an impostor answers and offers Bennett her old life back in exchange for the disk. She contacts the only other person who knows her by sight, psychiatrist and former lover Alan Champion (Dennis Miller). He checks her into a hotel, offers to contact a friend at the FBI, and arranges to have her mother moved for her safety.

Using her knowledge of the backdoor and a password found in Devlin's wallet, Bennett logs into the Bethesda Naval Hospital's computers and learns that Bergstrom, who had opposed Gatekeeper's use by the federal government, was misdiagnosed. Fellow hacker "Cyberbob" identifies π with the "Praetorians," a notorious group of cyberterrorists linked to recent computer failures around the country. Bennett and Cyberbob plan to meet at Pacific Park on the Santa Monica Pier, but the Praetorians intercept their online chat. Bennett escapes from Devlin—a contract killer for the cyberterrorists—at the park, but the Praetorians kill Champion by tampering with pharmacy and hospital computer records. After Bennett is arrested by the California Highway Patrol, a man identifying himself as Champion's FBI friend frees her from jail. She realises he is an impostor and escapes again.

Now wanted for murder, Bennett hitchhikes from Los Angeles to Cathedral's office in San Francisco where, using her impostor's computer, she connects the terrorists to Gregg Microsystems and uncovers their scheme; once the Praetorians sabotage an organization's computer system, Gregg sells his Gatekeeper product to them and gains unlimited access through the backdoor. Bennett emails evidence of the backdoor to the FBI from the Moscone Center and tricks Devlin into releasing a virus into Gregg's mainframe, undoing the erasing of her identity. They battle on the convention center's catwalks, where Devlin accidentally shoots and kills the impostor (the real Ruth Marx). Bennett then ambushes Devlin with a fire extinguisher, causing him to fall to his death. The film closes with Bennett reunited with her mother and the conspiracy exposed.

In October 1994, Bullock committed to filming The Net from mid-January through April 10, 1995.[3]The Net was filmed in San Francisco's Moscone Center and Macworld on January 5, 1995,[4] as well as at Washington, D.C. locations in April 1995.[5]

With an estimated budget of $22 million and a release date of 28 July 1995, The Net earned $50,727,965 in domestic box office. Including foreign markets, the film grossed $110,627,965 worldwide,[6] with an additional $23,771,600 in United States rentals.

Critical reaction to the film was mixed. Based on 47 reviews, it has an average score of 5.1 out of 10 on Rotten Tomatoes with 36% of critics giving a positive review.[7]Roger Ebert gave the film three out of four stars.[8]Owen Gleiberman, writing for Entertainment Weekly, complimented Sandra Bullock's performance, saying "Bullock pulls you into the movie. Her overripe smile and clear, imploring eyes are sometimes evocative of Julia Roberts".[9]

A sequel named The Net 2.0, starring Nikki DeLoach as Hope Cassidy and directed by Charles Winkler, son of Irwin Winkler, was announced in February 2005. It was released direct-to-video in 2006, and was about a young systems analyst who arrives in Istanbul for her new job to find that her identity has been stolen.